Re: [HACKERS] Small improvement to compactify_tuples - Mailing list pgsql-hackers

From Stephen Frost
Subject Re: [HACKERS] Small improvement to compactify_tuples
Date
Msg-id 20180123033429.GF2416@tamriel.snowman.net
Whole thread Raw
In response to Re: [HACKERS] Small improvement to compactify_tuples  (Юрий Соколов <funny.falcon@gmail.com>)
Responses Re: [HACKERS] Small improvement to compactify_tuples
List pgsql-hackers
Greetings,

* Юрий Соколов (funny.falcon@gmail.com) wrote:
> On Wed, Nov 29, 2017 at 8:00 AM, Peter Geoghegan <pg@bowt.ie> wrote:
> > On Tue, Nov 28, 2017 at 2:41 PM, Andres Freund <andres@anarazel.de> wrote:
> >> Maybe it's a stupid question. But would we still want to have this after
> >> the change? These should be just specializations of the template version
> >> imo.
>
> "generic" version operates on bytes, and it will be a bit hard to combine
> it with
> templated version. Not impossible, but it will look ugly.

If that's the case then does it really make sense to make this change..?

> In attach fixed qsort_template version.
> And version for compactify_tuples with bucket_sort and templated qsort.

While having the patch is handy, I'm not seeing any performance numbers
on this version, and I imagine others watching this thread are also
wondering about things like a test run that just uses the specialized
qsort_itemIds() without the bucketsort.

Are you planning to post some updated numbers and/or an updated test
case that hopefully shows best/worst case with this change?  Would be
good to get that on a couple of platforms too, if possible, since we've
seen that the original benchmarks weren't able to be consistently
repeated across different platforms.  Without someone doing that
leg-work, this doesn't seem like it'll be moving forward.

Marking as Waiting on Author.

Thanks!

Stephen

Attachment

pgsql-hackers by date:

Previous
From: Tom Lane
Date:
Subject: Re: [HACKERS] Patch: Add --no-comments to skip COMMENTs with pg_dump
Next
From: Amit Kapila
Date:
Subject: Re: [HACKERS] Parallel tuplesort (for parallel B-Tree index creation)